Members of a historical re-enactment group dressed as U.S. and Soviet Army soldiers take part in Elbe Day celebrations, in eastern German city of Torgau at the river Elbe, April 25, 2015. Elbe Day commemorates the encounter of the Allies 70 years ago, on the 25th of April 1945 when American and Soviet army units joined together on the destroyed bridge over the river Elbe. The photograph of the meaningful handshake made its way around the world and became a symbol of the near end of World War II in Europe. (Photo by Stefanie Loos/Reuters)

Hot air balloons take to the skies over Bristol city centre on August 6, 2012 in Bristol, England. The early morning flight of over twenty balloons over the city was organised as a curtain raiser for the four-day Bristol International Balloon Fiesta which starts on Thursday. Now in its 34th year, the Bristol International Balloon Fiesta is Europe's largest annual hot air balloon event in the city that is seen by many balloonists as the home of modern ballooning. (Photo by Matt Cardy)

Hot air balloons take to the skies as they participate in the mass assent at sunrise on the second day of the Bristol International Balloon Fiesta on August 11, 2017 in Bristol, England. More than 130 balloons have gathered for the four day event, now in its 39th year and now one of Europe's largest annual hot air balloon events, being hosted in the city that is seen by many as the home of modern ballooning. (Photo by Matt Cardy/Getty Images)

Korean War veteran Jon Sun Rye, 83 years old, walks after she paid respect to former leaders Kim Il-sung and Kim Jong-il at Mansu Hill in Pyongyang, North Korea, 15 April 2016. North Korea is marking the “Day of the Sun”, celebrating the day of birth of the country's founder, Kim Il-sung. The Day of the Sun is a national holiday. (Photo by Franck Robichon/EPA)

A young Shiite Muslim child participates in a Muharram procession in Ahmadabad, India, Sunday, October 9, 2016. (Photo by Ajit Solanki/AP Photo)

A cooling tower is seen under mechanical demolition in Binzhou, Shandong Province, China, July 13, 2016. (Photo by Reuters/China Daily)

This picture taken on November 18, 2015 shows young participants preparing to release a hot-air balloon during the Tazaungdaing Lighting Festival at Taunggyi in Myanmar's northeastern Shan State. Every year in November as the full moon approaches, tens of thousands of people from all over the country gather in Taunggyi for the colourful hot-air balloons festival during which balloons lift fireworks or lanterns which illuminate the sky at night while balloons of all shapes are flown during the day. (Photo by Ye Aung Thu/AFP Photo)

Hot air balloons fly over the sky in Chiang Mai province, northern Thailand, December 6, 2014. The two-day International Balloon festival 2014 featuring balloon pilots from Germany, Spain, Netherlands, Britain, and Czech Republic is held on December 06-07 2014 to celebrate Thai King Bhumibol Adulyadej's 87th birthday and also aimed to promote the tourism industry in Chiang Mai northern city. (Photo by Pongmanat Tasiri/EPA)